(AP) - Les Skramstad, a Libby, Mont. activist who became a public face for victims of absestos-related disease tied to the closed W.R. Grace and Co. vermiculite mine, has died, his son said Monday.

Skramstad, a former Grace mine worker, died Sunday morning at age 70, his son, Brent Skramstad said.

Skramstad had been diagnosed with mesothelioma _ a rare, fast-moving cancer that attacks the lining of the lungs _ about a month ago, his son said. He had several tumors in his stomach and had been previously diagnosed with asbestosis.

He was best known as a voice for many of Libby's sickened residents. He lobbied Congress for financial relief for those who could not pay their many medical bills.

The vermiculite, used in a variety of household products, contained tremolite asbestos, which was released into the air, carried home on miners' clothing. It is blamed by some health authorities for killing about 200 people and sickening one of every eight residents. Skramstad worked at the mine in the late 1950s and early 1960s.

Brent Skramstad said that he has also developed the disease, along with his sister and his mother, Norita.

"Hopefully there's somebody who will take his place now," Skramstad said of his father. "Because this is something you never want to be dropped. You want people to be held accountable for it."

In an interview last year, Les Skramstad said that of the 150 people he worked with four decades ago, only five are alive.

"It's going to kill us, every one of us," he said. "It's just a matter of time."